I think everyone is really missing the big picture on this one. When you are deciding to move either left or right when the nut will not seat on the screw what you are really seeing is the screw is out of alignment with the starting position. You have a 50/50 chance of getting it right which makes the pitch about an 1/8" off.
So, let's back up a little. First you must understand that the nut will only go back on the screw in one place. Here's something that might help. Take note of where the handle on the leadscrew is at when you start your spiral. Let's say it's in the upright position. When you end the spiral, lift your router and continue cranking the handle until it's in the same upright position. Now move back the amount you need to. It will magically seat in the right place. That's my input to this problem. We can also talk about backlash, but it does not really sound like the problem. I would never unlock and readjust the leadscrew or gears, but it can be done on special occasions. Unless your gears are skipping, it should never be needed. -Tim ----- Original Message ----- From: "George Scott" <gscot...@comcast.net> To: "Legacy Ornamental Mills" <legacy-ornamental-mills@googlegroups.com> Sent: Thursday, March 08, 2012 9:37 AM Subject: Split nut question > Well I.m spending some time on my 900 and wondering why I haven't done > this a long time ago. I,ve been having a small problem tho'....let's > see if I can explain in a way you can understand me. > > I have been doing some hollow spiral candle holders. Tracy has done a > couple versions...this is the one in which he used a 4 start rope > twist that is flattened with a core box bit and is called Hollow > Spiral, A New Twist on the Hollow Spiral. The first one I did went > very well except for milling the hollow spiral itself. > When I lined up the straight bit with the center of the spiral flute > (it's window nine in the online demo at the Legacy site) I am having > trouble keeping the bit centered when I tighten the split lock nut. I > suspect all of you have experienced how the nut will pull the router > left or right a fraction of an inch in order to lock into the screw > thread. > Well in this instance it moves the bit far enough to draw the cut off > center. It doesn't look good. For the life of me I can't see a > solution. No you can't turn the screw thread just a hair to get things > in line because it is linked to the gears which are driving the > spindle and this also puts it out of line. > As I sit here writing this I wonder if the only solution is to loosen > the gears and disengage everything, line up and reengage. Hmmmm > Thoughts anyone. > > Also considering a Z axis upgrade.....is $500 worth it. I guess I know > the answer to this, but...... what do you recommend? Those of you have > one....has it changed your life? > > George > > -- > You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. > To post to this group, send email to legacy-ornamental-mills@googlegroups.com. > To unsubscribe from this group, send email to legacy-ornamental-mills+unsubscr...@googlegroups.com. > For more options, visit this group at http://groups.google.com/group/legacy-ornamental-mills?hl=en. > -- You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. To post to this group, send email to legacy-ornamental-mills@googlegroups.com. To unsubscribe from this group, send email to legacy-ornamental-mills+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/legacy-ornamental-mills?hl=en.
